I used it on a honda accord I had. The rear passg side quarter panel had a hole from rust. cut out and sanded as much rust as I could then used that treatment, then sealed and primed it (after filling the hole with bondo lol , I wasnt planning on keeping the car so no reason to weld in new metal ) A few months later the paint starting bubbling up on that spot again. I guess I didn't get all the rust...or the stuff didn't do its job